1. Field of the Invention
The present invention relates to a control chip, and more particularly, to a control chip supporting a plurality of buses and a control chip set thereof.
2. Description of the Related Art
Information processing and exchange has become an inevitable process for new knowledge acquiring in this information explosion era. According to the importance of which, the developments of current technology target fast information processing and fast transmission by all means, thus distributed process environment becomes a common choice of the computer systems. In this distributed process computer system, various buses serve to transmit and receive data between chips for different purposes. As to the control chip set for current computer motherboard, there are the Peripheral Component Inter-connection Express (PCI Express) bus, the Hyper Transport (HT) bus, and the VLINK bus for communication between the north bridge chip and the south chip. Notice that the VLINK bus is developed by VIA Technologies Incorporated for chip sets communication. Therefore, the north bridge chip and the south bridge chip of different control chip set cannot be cooperated since different buses are used.
Under the above condition, in other words, a south bridge chip employing PCI Express bus only supports a north bridge chip employing the same bus, or the buses to the north and the south bridge chip for a certain CPU are required to be the same type of bus. According to current trend for personal computer or computer system development, the north bridge chip receives instructions from the CPU for DRAM and display control chip, and controls computer peripherals and storage media via south bridge chip. Thus job division is achieved in a computer system.
However, in accordance with futuristic trend to computer development, it is most likely to embed the memory controller in the north bridge chip in the CPU, and the north bridge chip is replaced with the south bridge chip, which is directly connected to the CPU. An issue is arose that different south bridge chips are associated with corresponding CPUs while different bus interfaces are applied. For a chip set design house, the south bridge chip commonly serves to connect slower computer peripheral devices (e.g. keyboard, mouse or floppy disk drive), yet the specifications of which have been unified so that significant variation is not expected in near future. If the south bridge chip has to be redesigned in order to comply with the bus specification used by the CPU or the north bridge chip, not only manufacturing cost will increase by noticeable amount, but also product in stock has to be monitored with care. These issues hence become major challenging tasks for the chip set design house.
Therefore, a chip supporting a plurality of bus specifications has been developed, wherein a driving circuit is used between external pins and device of the chip. Before the chip is embedded in a motherboard or a computer system, the driving circuit serves to modify the bus specification supported by the chip and the definition of the external pins. Therefore, the chip supports a plurality of bus specifications with the device, and thus cost to chip design and manufacturing is significantly reduced.